The effectiveness of the Mules operation when carried out in conjunction with lamb marking

Abstract

Seventy-eight Merino ewe lambs were Mulesed in September 1961 at the same time as their tails were docked (Marking Mules). For comparison, 76 lambs from the same drop were Mulesed in December 1961 (Weaning Mules). The modified Mules plus tail strip was used on both occasions. Observations on 13 un-Mulesed lambs showed three fly waves occurring during the course of the experiment -1. Late November-early December 1961-31 per cent of breech and tail strikes ; 2. April-May 1962-31 per cent; 3. September-November 1962-93 per cent. The Marking Mules gave effective protection during the first fly wave. Both operations reduced the incidence of strike during waves 2 and 3, totals of 11.7 and 5.6 per cent of strikes being recorded for the Marking Mules and Weaning Mules respectively. In comparison with the Marking Mules, the Weaning Mules produced slower healing of Mulesing wounds, greater post-operative depression of growth rate and reduced wool production.